Which one — mich or mir?

With both tables in your head, the real skill is choosing between them in the moment. There are only three questions to ask, and they are quick.

1. Is there a dative preposition (mit, zu, bei, von, nach, aus, seit)? → dative. 2. Is the verb a dative verb (helfen, gehören, danken, gefallen, antworten)? → dative. 3. Otherwise, is the pronoun the receiver and something else the thing? → dative. If none of these, use the accusative.

• Er fragt mich.

  He is asking me.

  plain object → accusative

• Er antwortet mir.

  He is answering me.

  dative verb → dative

• Ich sehe ihn.

  I see him.

• Ich helfe ihm.

  I am helping him.

• Ich kaufe ihr einen Kaffee.

  I am buying her a coffee.

  two objects: she receives (dative), the coffee is bought (accusative)

The double-object case in that last example is the clearest picture of the whole system: one verb, two objects, and German marks which is which by case rather than by word order. Ich kaufe ihr einen Kaffee and Ich kaufe sie einen Kaffee would mean quite different things — the second one is nonsense.